1. Field of the Invention
Embodiments of the invention relate to a stereoscopic image display.
2. Discussion of the Related Art
A stereoscopic image display implements a three-dimensional (3D) image using a stereoscopic technique or an autostereoscopic technique. The stereoscopic technique, which uses a parallax image between left and right eyes of a user with a high stereoscopic effect, includes a glasses type method and a non-glasses type method, both of which have been put on the market. In the glasses type method, a stereoscopic image is implemented on a direct-view display or a projector using polarized glasses by varying a polarization direction of the parallax image between the left and right eyes. Alternatively, the stereoscopic image is implemented on the direct-view display or the projector using liquid crystal shutter glasses by displaying the parallax image between the left and right eyes in a time-division manner. In the non-glasses type method, an optical axis of the parallax image between the left and right eyes is generally separated using an optical plate such as a parallax barrier and a lenticular lens, and thus the stereoscopic image is implemented.
FIG. 1 schematically illustrates a method for implementing a stereoscopic image by a related art patterned retarder type stereoscopic image display. As shown in FIG. 1, the patterned retarder type stereoscopic image display implements a stereoscopic image using polarization characteristic of a patterned retarder PR disposed on a display panel DIS and polarization characteristic of polarized glasses PG a user wears. The patterned retarder type stereoscopic image display displays a left eye image on odd-numbered lines of the display panel DIS and displays a right eye image on even-numbered lines of the display panel DIS. The left eye image passes through the patterned retarder PR and thus is converted into left-circularly polarized light. The right eye image passes through the patterned retarder PR and thus is converted into right-circularly polarized light. A left eye polarizing filter of the polarized glasses PG passes through only the left-circularly polarized light, and a right eye polarizing filter of the polarized glasses PG passes through only the right-circularly polarized light. Thus, the user views only the left eye image through his or her left eye and views only the right eye image through his/her right eye.
FIGS. 2A and 2B illustrate 3D image data input or output to a 3D formatter. More specifically, FIGS. 2A and 2B illustrate the 3D image data when a vertical resolution of a display panel is 1080. As shown in FIGS. 2A and 2B, a patterned retarder type stereoscopic image display converts the format of the 3D image data, so that the patterned retarder type stereoscopic image display can implement the 3D image data input using the 3D formatter in a patterned retarder manner. As shown in FIG. 2A, left eye image data 1L, 2L, 3L, 4L, . . . , 1079L, and 1080L of 1st to 1080th lines are input to the left half of the 3D image data input to the 3D formatter, and right eye image data 1R, 2R, 3R, 4R, . . . , 1079R, and 1080R of the 1st to 1080th lines are input to the right half of the 3D image data. As shown in FIG. 2B, in the patterned retarder manner, the 3D formatter arranges the left eye image data on odd-numbered lines and arranges the right eye image data on even-numbered lines to output the 3D image data. The display panel receives the 3D image data, whose the format is converted by the 3D formatter, and displays only a left eye image on the odd-numbered lines and only a right eye image on the even-numbered lines.
Because the patterned retarder type stereoscopic image display displays only the left eye image on the odd-numbered lines and only the right eye image on the even-numbered lines, a boundary of the 3D image is not smooth and may look like steps (step phenomenon). The step phenomenon is known as jagging, jagness, or zigzag artifact. In the following description, the step phenomenon is referred to as jagging.